Generally found on rocky reefs, where it prefers the shelter of crevices. Often seen in groups with antennae protruding from the shelter. Swims backwards in emergencies using the tail., but generally crawls around on the reef. Feeds on mussels, urchins and barnacles, but also a scavenger. Predators include seals, sharks and large fish. Susceptible to low oxygen levels in the water which may cause mass strandings.[4]

J. lalandii may grow up to a total length of 46 centimetres (18 in), with a carapace length of 18 cm (7.1 in). It is widely caught for its meat, with over 6,500 t being caught annually in lobster pots and hoop nets.[3] In order to prevent overfishing, individual fishing quotas are allocated by the Republic of South Africa to fishermen and companies, totalling 1,700 t.[5] There is also a closed season from 1 June to 15 November, a size limit of 80 mm (carapace length) and a ban on catching ovigerous females (females which are brooding their eggs).[6]